Previous work by the applicants has established models for the study of the immunology of murine bladder tumors. These tumors were found to cross react when lymphocytes from tumor immune hosts were tested with the microcytotoxicity assay in both the mouse and the rat system. Preliminary experiments have suggested immunologic protection against tumor induction in two types of experiment in the rat. A long term study of a group of patients with low stage bladder tumors has been undertaken and these patients are being followed with cell mediated immunity and serum stored for later measurements of serum blocking factors. We want to continue these studies with three specific aims: 1. to study cell mediated immune reactions to bladder tumor antigens and their blocking by serum in human patients with the emphasis on common tissue type specific antigens but also looking for unique antigens specific for each tumor and correlating this with the patient's clinical course. 2. to study, in parallel with the above, cell mediated immunity and humoral factors to common tissue type specific antigens and unique antigens to animal bladder papillomas and carcinomas, and to correlate these with tumor behavior in vivo. 3. to develop in the animal immunologic methods of preventing the induction of bladder tumors and of treating established tumors. Studies on the in vivo correlation of the in vitro immune responses in the human and in the animal model will be carried out in parallel. The animal models will then be used to develop methods of manipulating the immune response in order to increase tumor destruction in vivo. We believe that these studies will assist in the prediction of prognosis in the bladder tumor patient and ultimately lead to the development of a rational program of immunotherapy to add to the present modalities of radiation, surgery and chemotherapy.